Rotatable Catheter Assembly

ABSTRACT

A catheter assembly comprises a catheter shaft, a balloon and a pair of collars. The collars may be fixed or rotatable about a catheter shaft prior to exposure to an electric current. Where the collars are fixed to the shaft, the balloon is rotatable about the collars. When exposed to the electric current the collars expand to engage the waists of the balloon thereby sealing the balloon. Where the collars are rotatable about the shaft, the each waist of the balloon is engaged to a respective collars. When the rotatable collars are exposed to the electric current the collars expand to engage the shaft of the catheter thereby sealing the balloon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 10/785,449, filed Feb. 24, 2004, the entire disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

Stent delivery systems for deployment of one or more stent bodies at oraround a vessel bifurcation have been proposed. Often such stentsgenerally have an opening which allows for unimpeded blood flow into oneor more side branch arteries, and/or through which an additional stentbody may be deployed. However, problems are still encountered inorienting a stent relative to the side branch at the bifurcation of theprimary and secondary passages. Moreover, such bifurcated assemblies aretypically specially manufactured at an increased cost over a morestandard stent intended for single vessel deployment.

In delivering a stent to a vessel location, many current devices rely oneither passive torque (e.g., pushing the stent forward and allowing thestent that is fixed on the guidewire/balloon to passively rotate itselfinto place) or creating torque from outside of the patient to properlyorient the medical device in the passage. Such catheter assembliesinclude those described in U.S. Pat No. 5,749,825; U.S. Pat. No.6,599,315 and U.S. Pat. No. 6,290,673, the entire content of each ofwhich being incorporated herein by reference.

Unfortunately such devices still often require a significant portion ofthe catheter assembly in addition to the balloon to be subjected totorque in order to align the stent with the side branch opening of thebifurcation. Subjecting the catheter as well as a vessel to suchextraneous torque may be considered undesirable.

Thus, a need exists to provide a catheter which is capable of allowing amedical device such as a stent to be easily maneuvered and aligned at avessel bifurcation or other location without the need to torque orrotate the entire catheter shaft in order to align the stent at a vesselbifurcation. Various devices and methods described herein address thisneed by providing a catheter system with a rotatable balloon about whicha stent may be mounted on or engaged to. The rotatable balloon isindependently rotatable relative to the inner and/or outer cathetershafts thereby eliminating the need to apply torque to the cathetershaft to align the stent at a vessel bifurcation.

All U.S. patents and applications and all other published documentsmentioned anywhere in this application are incorporated herein byreference in their entirety.

Without limiting the scope of the invention, a brief summary of some ofthe claimed embodiments of the invention is set forth below. Additionaldetails of the summarized embodiments of the invention and/or additionalembodiments of the invention may be found in the Detailed Description ofthe Invention below.

A brief abstract of the technical disclosure in the specification isprovided as well only for the purposes of complying with 37 C.F.R. 1.72.The abstract is not intended to be used for interpreting the scope ofthe claims.

BRIEF SUMMARY OF THE INVENTION

As used herein, the term “stent” refers to an expandable prosthesis forimplantation into a body lumen or vessel and includes devices such asstents, grafts, stent-grafts, vena cava filters, etc. In someembodiments a stent may be at least partially constructed of any of avariety of materials such as stainless steel, nickel, titanium, nitinol,platinum, gold, chrome, cobalt, as well as any other metals and theircombinations or alloys. A stent may be at least partially constructed ofa polymer material. A stent may be at least partially constructed of ashape-memory polymer or material. A stent may be balloon expandable,self-expandable, hybrid expandable or a combination thereof. In someembodiments a stent may include one or more areas, bands, coatings,members, etc., that is (are) detectable by imaging modalities such asX-Ray, MRI or ultrasound. In some embodiments at least a portion of thestent is at least partially radiopaque. In some embodiments a stent mayinclude one or more therapeutic and/or lubricious coatings appliedthereto.

Some embodiments of the present invention are directed to cathetersystems wherein the catheter comprises balloon which is independentlyrotatable about the catheter shaft or shafts. For example, in at leastone embodiment the invention is directed to a catheter having an innershaft wherein a distal waist of the balloon is rotatably engaged and anouter shaft wherein a proximal waist of the balloon is rotatablyengaged. In some embodiments the catheter comprises only a singlecatheter shaft about which the balloon is rotatably engaged.

In at least one embodiment each balloon waist is disposed about acollar; the collar may be fixedly engaged to a portion of the cathetershaft or may be selectively rotatable there about. In at least oneembodiment a first portion of a catheter shaft has a collar engagedthereto; the collar may be fixed or rotatable thereabout. Where thecollar is fixed, a rotatable balloon is disposed about the cathetershaft in a manner such that each waist of the rotatable balloon isrotatably disposed about a collar. Where the collars are rotatable aboutthe catheter shaft, each waist of the balloon is fixedly disposed to theouter surface of a collar so that the balloon is made rotatable aboutthe catheter shaft as a result.

The collars are at least partially constructed of an electro-activepolymer (EAP) which expands to a predetermined extent upon exposure toan electric current. In some embodiments the collars are exposed to theelectric current by a conductive element. A second conductive element isprovided by exposing the fluid that inflates the balloon, which istypically saline and/or a radiopaque solution) to a similar electricalcurrent. In some embodiments the EAP material of the collar and/or thecollar itself will expand about 0.5% to about 20% expansion in apredetermined manner and/or direction when subjected to an electriccurrent of 0.001 microAmps to 1 milliAmps (−2 to +2 V). In at least oneembodiment a collar is constructed of one or more conductive elementssuch as gold, silver, platinum, etc., which is at least partiallysurrounded by a layer of EAP material.

In embodiments where the collars are rotatable about the catheter shaft,prior to exposure to the electric current, the collars define an insidediameter which is sufficiently greater than the outer diameter of thecatheter shaft to which they are respectively engaged so as to allow thecollars, and thus the balloon mounted thereto, to freely rotate aboutthe catheter shaft(s). When the collars are exposed to the electriccurrent through one or more conductive members within and/or adjacent tothe catheter, the collars will expand and thus effectively contractaround the respective catheter shaft to which they are engaged,effectively sealing the interior of the balloon which may then beexpanded.

In embodiments where the collars are fixed to the catheter shaft, priorto exposure to the electric current, the collars define an outsidediameter which is sufficiently less than the inner diameter of thecatheter waists which are respectively disposed there about so as toallow the waists, and thus the balloon body extending there between, tofreely rotate about the collars. When the collars are exposed to theelectric current through one or more conductive members within and/oradjacent to the catheter, the collars will expand and thus effectivelypush against the respective catheter waists, effectively sealing theinterior of the balloon, which may then be expanded.

In order to get an electric current to a collar, in some embodiments aconductive wire or member of gold, gold plated SS, Nitinol, silvercoated SS, Elgiloy®, etc., extends from a current source to a collarthrough or adjacent to the catheter shaft. In some embodiments theconductive member is in the form of an insulated wire or other memberwhich engages the collar via an exposed end which extends through anopening in the catheter shaft. Such a member may be co-extruded with oneor more catheter shafts and/or balloon. A proximal end of the wire isengaged to a current source which may be activated to transmit thecurrent through the wire to the collar when desired. In at least oneembodiment a conductive member is at least partially contained withinone or more lumens defined by the catheter.

In some embodiments a collar is bonded, welded, adhesively engaged,mechanically engaged or otherwise fixed to a balloon waist. In someembodiments a collar is bonded, welded, adhesively engaged, mechanicallyengaged or otherwise engaged to a portion of the catheters shaftunderlying a waist of the balloon which is rotatable thereabout. In someembodiments, where the collar is fixed to a balloon waist the waist maybe reinforced with one or more layers of transition material positionedbetween the collar and the balloon waist in order to facilitateengagement there between. In some embodiments the waist may likewise bereinforced. In some embodiments a transition material includes but isnot limited to: Plexar®, Selar®, EMS Hytrel®, and other similarmaterials. In at least one embodiment the collar is integral with theballoon waist. In at least one embodiment the collar is integral withthe catheter shaft. In at least one embodiment a collar comprises onlyEAP material.

In some embodiments the catheter comprises one or more support membersor rings which support the region of the catheter shaft(s) about whichthe collars are mounted. A support ring may be constructed of one ormore materials including but not limited to: Polyamide, Nylon, Pebax®,Acetyl, PTFE, HDPE, PI, PET, Christamid, Vestimid, metal reinforcedpolymers, braided reinforced polymers, Stainless steel, Nitinol, etc.

In some embodiments the catheter is disposed about a primary guidewire.In at least one embodiment the catheter is a fixed wire catheter. Insome embodiments a secondary guidewire housing through which a sidebranch or secondary guidewire is positioned. In some embodiments thesecondary guidewire housing is engaged to the balloon. In at least oneembodiment the secondary guidewire housing is positioned at leastpartially under the stent prior to delivery.

In some embodiments the secondary guidewire extends into a side branchof a bifurcation through a secondary opening of the stent. By advancingthe catheter along the secondary guidewire as the catheter is advancedthrough the main vessel to the bifurcation, rotation will be imparted tothe balloon to orient the secondary opening of the stent and/or thesecondary guidewire housing with the side branch of the vesselbifurcation. When properly oriented the collars are subjected to anelectric current thereby imparting the balloon with a fluid sealsufficient to allow inflation of the balloon.

These and other embodiments which characterize the invention are pointedout with particularity in the claims annexed hereto and forming a parthereof. However, for a better understanding of the invention, itsadvantages and objectives obtained by its use, reference should be madeto the drawings which form a further part hereof and the accompanyingdescriptive matter, in which there is illustrated and describedembodiments of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS(S)

A detailed description of the invention is hereafter described withspecific reference being made to the drawings.

FIG. 1 is a perspective view of an embodiment of the inventioncomprising a catheter assembly having a rotatable balloon;

FIG. 2 is a longitudinal cross-sectional view of an embodiment of theinvention being advanced to a vessel bifurcation and prior to balloonexpansion;

FIG. 3 is a longitudinal cross-sectional view of the embodiment shown inFIG. 2 shown during expansion of the balloon;

FIG. 4 is a longitudinal cross-sectional view of an embodiment of theinvention being advanced to a vessel bifurcation and prior to balloonexpansion;

FIG. 5 is a longitudinal cross-sectional view of the embodiment shown inFIG. 4 shown during expansion of the balloon;

FIG. 6 is a block diagram illustrating the conductive relationship ofthe catheter assembly shown in FIG. 1 with a source of electric current;

FIG. 7 is a longitudinal cross-sectional view of an embodiment of theinvention;

FIG. 8 is an enlarged partial side view of a collar such as may beutilized by the embodiment shown in FIG. 1 shown prior to exposure to anelectric current;

FIG. 9 is an enlarged partial side view of the collar illustrated inFIG. 8 shown during exposure to an electric current;

FIG. 10 is a partial side view of the balloon shown in FIG. 1 with astent and guidewire housing shown engaged thereto;

FIG. 11 is a close up view of a secondary opening of a region of theassembly shown in FIG. 1.

FIG. 12 is a cross-sectional view of the balloon shown in FIG. 10;

FIG. 13 is a longitudinal cross-sectional view of the stent depicted inFIGS. 10-12 shown after delivery and withdrawal of the catheterassembly;

FIG. 14 is a longitudinal cross-sectional view of an embodiment of theinvention wherein the catheter assembly comprises a single cathetershaft;

FIG. 15 is a longitudinal cross-sectional view of an embodiment of theinvention wherein the balloon wall comprises a conductive member inconductive communication with the proximal and distal collars;

FIG. 16 is a partial view of a catheter assembly showing an optionalengagement configuration between the balloon waist and the collar;

FIG. 17 is a partial view of a catheter assembly showing an optionalengagement configuration between the balloon waist and the collar;

FIG. 18 is a partial view of a catheter assembly showing an optionalengagement configuration between the balloon waist and the collar; and

FIG. 19 is a partial view of a catheter assembly showing an optionalengagement configuration between the catheter shaft and the collar.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there aredescribed in detail herein specific embodiments of the invention. Thisdescription is an exemplification of the principles of the invention andis not intended to limit the invention to the particular embodimentsillustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated.

Referring now to the drawings which are for the purposes of illustratingembodiments of the invention only and not for purposes of limiting same,in at least one embodiment of the invention, an example of which isshown in FIG. 1, a catheter assembly 10 comprises an inner cathetershaft 12, an outer catheter shaft 14 and a rotatable balloon 16rotatably engaged to one or both shafts 12 and 14.

Balloon 16 may be a typical angioplasty, stent delivery balloon or otherinflatable member which may be used or incorporated into a catheterassembly. Typically the wall thickness of the waists 20 and 22 of theballoon 16 will be thicker than the thickness of the balloon body whichextends there between. In some cases the thickness of one or both waistsis about twice that of the balloon body but may be about 10 times moreresistant to radial pressures.

In order to allow the balloon 16 to rotate freely relative to the shaftor shafts 12 and 14 each waist 20 and 22 of the balloon 16 is engaged toa collar 30 and 32 respectively. Collars 30 and 32 are at leastpartially constructed of EAP material such including of Poly-pyrrole(PPY), Poly-Aniline (PAni), Poly-Thiofene (PTH), Poly-ParaphenyleneVinylene (PPV), Nafion®, Bucky paper or any other ionic electro-activepolymer that is considered to have low voltage, low speed, high stress(up to 500 MPa), characteristics. EAP materials have the uniquecharacteristic of expanding in size when exposed to an electric currentof predetermined current or voltage. For example, in some embodimentsthe EAP material of the collar and/or the collar itself will expandabout 0.5% to about 20% when exposed to an electric current of 0.001microAmps to 1 milliAmps (−2 to +2 V).

EAP materials and some of their notable characteristics are described inan article entitled Electro-Active Polymer Actuators for PlanetaryApplications by Y. Bar-Cohen et al. and published in Paper No. 3669-05of the Proceedings of SPIE Annual International Symposium on SmartStructures and Materials, March 1999, Newport Beach, Calif. SPIECopyright 1999, the entire contents of which being incorporated hereinby reference.

As a result of EAP materials' unique expansion characteristics, a collarcomprising EAP material such as collars 30 and 32 may be formed to havea pre-current shape and a post-current shape that is different or largerthan the pre-current shape.

Pre-current refers to the condition of the collars 30 and 32 before thecollars are exposed to an electric current sufficient to activate theEAP material. Post-current refers to the condition of the collars 30 and32 when the collars are being exposed to an electric current sufficientto activate the expansion of the EAP material.

In some embodiments the collars 30 and 32 in the pre-current state areconstructed to rotate freely about the respective catheter shafts 12 and14 and to become fixed in position and engagement to the respectivecatheter shafts 12 and 14 in the post current state. In suchembodiments, an example of which is shown in FIG. 2, collars 30 and 32are provided with a pre-current inner diameter, which is sufficientlygreater than the outer diameter of the shafts 12 and 14 to allow thecollar, and thus the balloon 16 engaged thereto, to freely rotate aboutthe shafts 12 and 14 before exposure to the electric current.

When the collars 30 and 32 are exposed to an electric current,illustrated by arrows 62, the expansion of the EAP material causes theinner diameter of the collars to expand such as is shown in FIG. 3. As aresult, each collar 30 and 32 will contract around their respectivecatheter shafts 12 and 14, effectively sealing the collars 30 and 32thereto. As a consequence of the collars 30 and 32 being sealed againstthe shafts 12 and 14, the interior 40 of the balloon 16 is madeeffectively fluid tight against the shafts thereby allowing the balloonto be expanded such as by inflation via an inflation fluid throughinflation lumen 42.

In some embodiments, an example of which is shown in FIG. 4, the collars30 and 32 are fixedly engaged about shafts 12 and 14, respectively. Inthe pre-current state, the balloon 16 is rotatably disposed about thecollars 30 and 32 such that the distal waist 20 of the balloon 16 isrotatably disposed about the distal collar 30, and the proximal waist 22of the balloon 16 is rotatably disposed about the proximal collar 32 ofthe balloon 16. In the pre-current state each collar 30 and 32 has anouter diameter less than the inner diameter defined by the respectiveballoon waists 20 and 22. In the post-current state the collars 30 and32 expand outward to engage the waists 20 and 22 such as in the mannershown in FIG. 5. By engaging the waists 20 and 22 in this manner theinterior 40 of the balloon 16 is made effectively fluid tight againstthe collars 30 and 32 thereby allowing the balloon to be expanded suchas by inflation via an inflation fluid through inflation lumen 42.

In some embodiments, such as in the example shown in FIGS. 2-5, it maybe beneficial to support the distal end of the outer shaft 14 with asupport ring or member 17. The support ring may be disposed about theinner shaft 12 and/or may be merely internally engaged to the outershaft 14. In some embodiments the ring 17 extends between the innershaft 12 and the outer shaft 14, but defines one or more openingstherethrough which further define the inflation lumen 42. Ring 17 may beconstructed of one or more materials including but not limited to:stainless steel coil, stainless steel stent like structure, stainlesssteel spiral cut hypotube, Nitinol, acetyl, PI, HDPE, LX2/TR55,Nanocomposites, Ceramics. In some embodiments the length of the ring 17will be approximately the same length as the collar 32 and/or 30 whichit supports.

In some embodiments the inner shaft 12 has one or more bands 56 ofradiopaque material. In some embodiments a band(s) 56 is detectable byimaging modalities such as X-Ray, MRI or ultrasound.

As shown in FIGS. 2-5, one or more conductive wires or other members 50may extend from a proximal region of the catheter 10 to the collars 30and 32. A current source 60 as depicted in FIG. 6 is in communicationwith the wire(s) 50 which when activated transmits the electric current,illustrated by arrows 62 in FIGS. 2-5, to the wires 50 and collars 30and 32, thereby causing expansion of the EAP material in the collars tosealingly engage the balloon 16 to the shafts 12 and 14. The circuitwhich the current traverses through the members 50 and collars 30 and 32may be completed as a result of the conductive nature of the saline orother fluid 300 which is used to expand the balloon 16. In some casesthe conductive nature of some bodily fluids may also be utilized tocomplete the circuit.

Wires 50 maybe co-extruded with the material of either or both cathetershafts 12 and 14. An opening 15 in the shaft(s) exposes the wire 50 tothe collars 30 and 32 in the manner shown in FIGS. 2-5. Alternatively,the catheter assembly 10 may define any number of lumens through which awire or wires may be positioned. In some embodiments a wire 50 mayextend at least partially through the inflation lumen 42 to one or bothcollars 30 and 32.

As indicated above, the collars 30 and 32 are at least partiallyconstructed of one or more EAP materials. However, in order to moreeffectively transmit the electric current to the EAP material in someembodiments, such as shown in FIGS. 2-5, the collars 30 and 32 include aconductive member or marker 34 about which at least one layer 36 of EAPmaterial is engaged. The markers 34 may be any type of conductivematerial or materials and is preferably biocompatible. Appropriatematerials for the construction of the markers 34 include, but are notlimited to, gold, platinum, nitinol, silver, etc. The layer 36 of EAPmaterial may partially or entirely surround the marker 34.

In the embodiment depicted in FIGS. 2-5, the collars 30 and 32 areconstructed so that at least a portion of the inside surface of thecollar is defined by a marker 34. This allows direct contact of theconductive material of the marker to be directly engaged to theconductive wire 50. In this manner the current received by the markermay be distributed to the surrounding layer of EAP material in asubstantially uniform manner to allow the EAP material engaged theretoto expand in a substantially uniform manner.

As illustrated in FIG. 1 the catheter may be equipped with one or morehubs, tips, rings or other devices 90 and/or 92 which may abut thecollars 30 and/or 32 to limit the potential for undesired longitudinalmigration of the balloon 16 relative to the catheter shafts 12 and 14.In the embodiment shown in FIG. 7, the outer shaft 14 is provided with anecked region 91 wherein the outer and/or inner diameter of the shaft 14narrows adjacent to the proximal collar 32. The reduced diameter neckedregion 91 may include a step or shoulder 93 which may abut the proximalcollar 32 and/or proximal waist 22, thereby preventing longitudinalmigration of the balloon 16 in the proximal direction.

As is also shown in FIG. 7, in some embodiments the distal hub may be inthe form of the catheter tip 92 which distally abuts the proximal collar30 and/or proximal waist 20 thereby preventing longitudinal migration ofthe balloon 16 in the distal direction.

In some embodiments where the collars 30 and 32 are rotatable about thecatheter shaft in the pre-current state, in some cases the collars 30and 32 may avoid the need for hubs by rotatably disposing the collars 30and/or 32 to a conductive ring 52 such as in the manner depicted inFIGS. 8 and 9. In the embodiment shown in FIGS. 8 and 9 the conductivewire 50 may further comprise a conductive ring 52 which projectsradially outward from the catheter shaft 12/14. The EAP layer 36 and/orthe marker 34 of a collar 30/32 may define a groove or track 38 which isrotatably engaged to the ring 52 prior to exposure of the collar to theelectric current. When current 62 is supplied to the ring 52, and thusthe collar 30/32 as well, the layer 36 of EAP material will expand toclose the groove against the ring 52 and seal the collar 30/32 about theshaft 12/14.

In the various embodiments shown in FIGS. 2-5, prior to electricactivation of the collars 30 and 32, the balloon 16 is freely rotatableabout the catheter shafts 12 and 14. This capacity to freely rotateallows a stent 70 mounted on the balloon 16 to be rotationally orientedwithin a body vessel 100 during advancement of the assembly 10 withoutnecessitating torquing of the catheter shafts 12 and/or 14. Because theballoon 16 is freely rotatable, it is desirable to provide the balloon16 with a mechanism which allows the balloon 16 to be rotated to adesired position.

In the various embodiments described herein, the catheter assembly 10may be a fixed wire catheter or any other catheter design. In theembodiment depicted in FIGS. 1-5, for example, the catheter is an overthe wire design wherein the inner shaft 12 defines a primary guidewirelumen 11 along which a primary guidewire 13 may be advanced.

In some embodiments, such as are illustrated in FIGS. 1-5, such amechanism is comprised of a secondary guidewire housing 80. Housing 80maybe comprised of a tubular member which defines a secondary guidewirelumen 84 through which a secondary guidewire 86 may be advanced. Thehousing 80 is engaged to the balloon 16 or defined by the balloon wallas desired. The housing 80 may be comprised of one or more tubularmembers 82. Where multiple members 82 are included in the housing 80,the members are disposed about one another to provide the housing with avariety of flexibility, hardness, and/or stiffness characteristics asdesired. As such, the housing 80 maybe constructed of any of a widevariety of materials including metal(s), polymer(s), natural rubber,silicone, multilayer materials, urethanes, Pebax®, HDPE, etc.

When the stent 70 is properly positioned on the balloon 16, such as inthe manner depicted in FIGS. 1-5, a proximal portion 72 of the stent 70is also disposed about at least a portion of the secondary guidewirehousing 80. When the stent 70 is thusly positioned about the balloon 16and the housing 80, in some embodiments, such as for example that shownin FIGS. 10 and 11, at least a portion of the housing 80 and/or thesecondary guidewire 86 extends distally through a cell opening 76 of thestent 70.

Stent 70 may be a stent, such as is shown in FIG. 10, which is at leastpartially constructed of a plurality of interconnected struts,connectors or members 75. The stent 70 defines a proximal opening 71, adistal opening 73 and a flow path 77 therebetween. The cell openings 76are in fluid communication with the flow path 77.

When the secondary guidewire 86 and/or the secondary guidewire housing80 is threaded through one of the cell openings 76 when the stent ispositioned onto the assembly 10, such as is shown in FIGS. 1, and 10-12,the members 75 that define the selected cell opening 78, as well as theshape of the opening 78 through which the secondary guidewire 86 exitsthe stent, may be distorted or modified in order to accommodate thepassage of secondary guidewire 86 and/or the secondary guidewire housing80 therethrough.

This modified cell opening 78, hereinafter referred to as secondaryopening 78, is positioned on the stent 70 between the proximal opening71 and the distal opening 73. The manner in which the secondary opening78, the members 75 adjacent thereto, and to an extent the stent 70itself, are modified or distorted by the position of the secondaryguidewire and/or secondary guidewire housing is best illustrated inFIGS. 10 and 12.

It should be noted that when the stent 70 is placed on the balloon 16 inthe manner described above, the distortion of the secondary opening 78and the adjacent members 75 may be of a minimal nature providing only asufficient alteration to the cell to allow sliding passage of thesecondary guidewire 86 and, if desired, a distal portion of thesecondary guidewire housing 80 therethrough. As such, the actual size ofthe secondary opening 78 may be substantially similar, or onlymarginally different than that of the surrounding cell openings 76.

It should be further noted that while stent 70 may be a standard “singlevessel” stent that is provided with a secondary opening 78 in the mannerdescribed above, the stent 70 may also be a bifurcated stent having atrunk and/or stem portion, with one or more leg portions and/or branchopenings adjacent thereto, through which the secondary guidewire may bepassed. Such bifurcated stents and stent assemblies are well known inthe art.

In some embodiments, the secondary guidewire 86 is merely slid betweenthe balloon 16 and the stent 70 without the use of a housing 80. In someembodiments, where the stent 70 is to be positioned substantiallyproximal to a side branch of the bifurcation, the guidewire 86 and/orhousing 80 may be configured to extend under the entire length of thestent 70.

In operation, the secondary guidewire 86 is initially advanced throughthe vessel 100 and into a side branch 102 of a bifurcation 104. Byadvancing the catheter assembly 10 along the secondary guidewire 86 inthe manner described above, the balloon 16 and the stent 70 disposedthereabout will be rotated to align the secondary opening 78 of thestent 70 with the side branch vessel 102. Once properly positioned inthis manner, the to collars 30 and 32 may be activated and the balloon16 expanded to deliver the stent 70 such as in the manner depicted inFIGS. 3 and 5. As shown in FIG. 13, once the stent 70 is delivered theballoon is deflated and the assembly is withdrawn from the vessel 100.

In some cases, the stent 70, or one or more portions of the assembly 10thereof, may be configured to deliver one or more therapeutic agents toa delivery site within the vessel 100 or one or more areas adjacentthereto such as shown in FIGS. 2-5.

To better accommodate placement of a therapeutic agent on the stent 70,in some instances one or more stent members 75, such as is shown in FIG.10, maybe configured to include one or more holes, notches, or othersurface features to which one or more therapeutic agents 200 may beplaced for delivery to the aneurysm site. A therapeutic agent may beplaced on the stent in the form of a coating. Often the coating includesat least one therapeutic agent and at least one polymer.

A therapeutic agent may be a drug, a non-genetic agent, a genetic agent,etc. Some examples of suitable non-genetic therapeutic agents includebut are not limited to: anti-thrombogenic agents such as heparin,heparin derivatives, urokinase, and PPack (dextrophenylalanine pralinearginine chloromethylketone); anti-proliferative agents such asenoxaprin, angiopeptin, monoclonal antibodies capable of blocking smoothmuscle cell proliferation, hirudin, and acetylsalicylic acid;anti-inflammatory agents such as dexamethasone, prednisolone,corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine;antineoplastic/antiproliferative/anti-miotic agents such as paclitaxel,5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones,endostatin, angiostatin and thymidine kinase inhibitors; anestheticagents such as lidocaine, bupivacaine and ropivacaine; anti-coagulantssuch as D-Phe-Pro-Arg chloromethyl keton, an RGD peptide-containingcompound, heparin, antithrombin compounds, platelet receptorantagonists, anti-thrombin antibodies, anti-platelet receptorantibodies, aspirin, prostaglandin inhibitors, platelet inhibitors andtick antiplatelet peptides; vascular cell growth promoters such asgrowth factor inhibitors, growth factor receptor antagonists,transcriptional activators, and translational promoters, vascular cellgrowth inhibitors such as growth factor inhibitors, growth factorreceptor antagonists, transcriptional repressors, translationalrepressors, replication inhibitors, inhibitory antibodies, antibodiesdirected against growth factors, bifunctional molecules consisting of agrowth factor and a cytotoxin; bifunctional molecules consisting of anantibody and a cytotoxin; cholesterol-lowering agents; vasodilatingagents; and agents which interfere with endogenous vascoactivemechanisms, and any combinations thereof.

Where an agent includes a genetic therapeutic agent, such a geneticagent may include but is not limited to: anti-sense DNA and RNA; DNAcoding for anti-sense RNA, tRNA or rRNA to replace defective ordeficient endogenous molecules; angiogenic factors including growthfactors such as acidic and basic fibroblast growth factors, vascularendothelial growth factor, epidermal growth factor, transforming growthfactor a and β platelet-derived endothelial growth factor,platelet-derived growth factor, tumor necrosis factor a, hepatocytegrowth factor and insulin like growth factor; cell cycle inhibitorsincluding CD inhibitors, thymidine kinase (“TK”) and other agents usefulfor interfering with cell proliferation; at least one of the family ofbone morphogenic proteins (“BMP's”) such as BMP-2, BMP-3, BMP-4, BMP-5,BMP-6 (Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11, BMP-12,BMP-13, BMP-14, BMP-15, and BMP-16. Any of BMP-2, BMP-3, BMP-4, BMP-5,BMP-6 and BMP-7; dimeric proteins such as homodimers, heterodimers, orcombinations thereof, alone or together with other molecules; moleculescapable of inducing an upstream or downstream effect of a BMP such as“hedgehog” proteins, or the DNA's encoding them and any combinationsthereof.

Where a therapeutic includes cellular material, the cellular materialmay include but is not limited to: cells of human origin (autologous orallogeneic); cells of non-human origin (xenogeneic) and any combinationthereof. Some examples of cellular material include but are not limitedto the following:

-   SP—(side population cells) These cells are thought to be some of the    most primitive adult stem cells. They are isolated by a specific    FACS technique utilizing the ability of SP cells to exclude Hoechst    dye from the nucleus. In addition to bone marrow, SP cells have been    isolated from most tissues, including: cardiac and skeletal muscle.    By the more common surface protein identification these cells are    Lin⁻, Sca-1⁺, c-Kit⁺, CD43⁺, CD45⁺, CD34⁻.-   Lin⁻—(lineage negative cells) This group of cells is isolated from    the bone marrow, and all cells which have differentiated to a    specific lineage (e.g., red blood cells) have been removed,    therefore leaving all of the stem and progenitor cells. This is    beneficial because all primitive cells remain, but may reduce    efficiency by including irrelevant, primitive cell types.-   Lin⁻CD34⁻—Although CD34⁺ cells have received much attention, many    articles have been published lately which suggest the most primitive    bone marrow derived stem cells are CD34⁻.-   Lin⁻CD34⁺—Presence of the cell surface protein CD34 has been used to    identify hematopoietic stem cells. However, the marker is also    present on progenitor cells and white blood cells of various levels    of maturity.-   Lin⁻cKit⁺—cKit is the cell surface receptor for stem cell factor,    and therefore a logical choice for stem cell selection. Most widely    studied from bone marrow sources, but have also been isolated from    the heart.-   MSC—(mesenchymal stem cells) Named so because ordinarily these cells    differentiate into cells of mesenchymal tissues (e.g., bone,    cartilage, fat), but may also differentiate into cardiomyocytes    under certain conditions. Easily isolated from bone marrow and,    unlike hematopoietic stem cells, proliferate in vitro. A    subpopulation of MSCs has been shown to self-renew faster and have a    greater potential for multipotential differentiation than the    general MSC population. D. Prockop from Tulane U. is publishing in    this area.-   Cord Blood Cells—Derived from the blood remaining in the umbilical    vein following child birth. This blood has been shown to contain a    higher percentage of immature stem cells or progenitor cells.    Typically, a matched donor must be found for patients, but a lower    incidence of graft versus host disease compared to stem cell    isolation from adult blood has been reported. Disadvantages include:    insufficient cell number in small blood volumes, unforeseen    congenital defects, and contamination by mother's blood which is    likely not HLA matched.-   Cardiac or other tissue derived stem cells—Most work to date has    focused on isolating stem cells from bone marrow. This is due to    extensive work in improving bone marrow transplants for chemotherapy    and leukemia treatments. However, there is evidence that similar    stem cells which can be identified by similar means (e.g., SP, cKit)    can be isolated from other tissues (e.g., fat, cardiac muscle).-   Whole bone marrow—An “it's in there” approach where whole bone    marrow (filtered for bone particles) is transplanted. Benefits    include: little processing, all stem and progenitor cells are    present, and matrix proteins and growth factors may also be present.    Downside—if one or two stem cell types are responsible for cardiac    improvement they will only be present in very low numbers.-   BM-MNCs—(bone marrow mononuclear cells) Separated from whole bone    marrow by a density gradient centrifugation procedure, this    population contains non-granular white blood cells, progenitor    cells, and stem cells.-   EPCs—(endothelial progenitor cells) Isolated from bone marrow based    on cell surface markers, these cells will become endothelial cells.    In theory, these cells will form new blood vessels when delivered to    ischemic tissue.-   Skeletal myoblasts—(or satellite cells) These cells are responsible    for the regeneration of skeletal muscle following injury. They have    the ability to fuse with other myoblasts or damaged muscle fibers.    Cardiac muscle therapies assume these cells can integrate into the    host tissue and improve tissue properties or functionally    participate in contraction.-   MDCs—(muscle derived cells) A population of cells isolated from    adult skeletal muscle which are similar to myoblasts. The isolation    technique preplating entails collecting cells which attach to    culture dishes at different times after biopsy. Cells with the best    potential plate in the 6^(th) group and takes several days to    obtain. Investigators working with these cells claim they are a    refined population of myoblasts and should result in higher    engraftment efficiencies and efficacious procedures.-   Go cells—Recently isolated from adult skeletal muscle, these    non-satellite cells express GATA-4 and, under certain in vitro    growth conditions, progress to spontaneously beating    cardiomyocyte-like cells.-   Endothelial cells—Transplantation of autologous endothelial cells    along with a fibrin matrix induced angiogenesis and improved cardiac    function in an ischemic sheep model.-   Adult cardiomyocytes-   Fibroblasts—Easily obtained from adult tissues, fibroblasts may    provide growth factors or participate in the wound healing response.    Fibroblast play a critical role in wound healing; the synthesis and    deposition of extracellular matrix. Fibroblasts commonly become    contractile in wound healing environments.-   Smooth muscle cells—Isolated from arteries, these cells may    participate or encourage angiogenesis and/or beneficial cardiac    remodeling following MI.-   MSCs+5-aza—Culture of mesenchymal stem cells with 5-aza forces    differentiation into cardiomyocytes. These cells beat spontaneously    after treatment.-   Adult cardiac fibroblasts+5-aza—In theory, in vitro treatment of    cardiac fibroblasts with 5-aza will result in differentiation into    myogenic cells.-   Genetically modified cells—Isolation of cells from the patient and    genetically modifying them in vitro to encourage production of    proteins or differentiation into a cell type which will be    beneficial for treating heart failure.-   Tissue engineered grafts—Isolation of cells from the patient which    are then seeded onto and cultured within resorbable scaffolds (e.g.,    collagen, PLGA). These cell seeded constructs are then implanted    into the patient.-   MyoD scar fibroblasts—MyoD family of transcription factors prompt    skeletal muscle cell differentiation in fibroblasts. Procedure    involves isolation of cardiac scar fibroblasts, genetic transfection    with MyoD in vitro and delivery of the cells to the heart to    encourage myogenesis.-   Pacing cells—Genetically modified fibroblasts which become    electrically conducting and signal generators.-   Embryonic stem cell clones—Use of cloning technology to produce    cardiomyocytes, progenitors, or stem cells which are genetically    identical to the patient.-   Embryonic stem cells—These cells are the most primitive of cells and    will differentiate into functional cardiomyocytes under certain    conditions. Both political and technological hurdles must be    overcome before commercialization of this technology.-   Fetal or neonatal cells—Isolated from the heart of donors, these    cells may incorporate into host tissue without immune rejection.    Some cardiomyocyte progenitor cells must be present due to the    continued growth of the heart in fetal and neonatal humans.-   Immunologically masked cells—Allogeneic cell sources (e.g., donor    cardiomyocytes) are currently unfeasible due to immune rejection.    However, masking technologies have been developed which could make    this technology feasible.-   Tissue engineered grafts—Isolation of cells from a donor which are    then seeded onto and cultured within resorbable scaffolds (e.g.    collagen, PLGA). These cell seeded constructs are then implanted    into the host or recipient.-   Genetically modified cells—Isolation of cells from a donor and    genetically modifying them in vitro to encourage production of    proteins or differentiation into a cell type which will be    beneficial for treating heart failure. The modified cells will then    be transplanted into the host or patient.-   Teratoma derived cells—A teratocarcinoma is a form of cancer in    which the tumor is composed of a heterogeneous mixture of tissues.    Through isolation of cells from this tumor and in vitro manipulation    and culture a neuronal cell line has been developed. Layton    Biosciences has successfully used these cells to form new brain    tissue in stroke patients. Similar techniques may be used to produce    a myogenic cell line.

Where a therapeutic agent comprises at least one polymer agent orcoating, the at least one coating may include but is not limited to:polycarboxylic acids; cellulosic polymers, including cellulose acetateand cellulose nitrate; gelatin; polyvinylpyrrolidone; cross-linkedpolyvinylpyrrolidone; polyanhydrides including maleic anhydridepolymers; polyamides; polyvinyl alcohols; copolymers of vinyl monomerssuch as EVA; polyvinyl ethers; polyvinyl aromatics; polyethylene oxides;glycosaminoglycans; polysaccharides; polyesters including polyethyleneterephthalate; polyacrylamides; polyethers; polyether sulfone;polycarbonate; polyalkylenes including polypropylene, polyethylene andhigh molecular weight polyethylene; halogenated polyalkyl enes includingpolytetrafluoroethylene; polyurethanes; polyorthoesters; proteins;polypeptides; silicones; siloxane polymers; polylactic acid;polyglycolic acid; polycaprolactone; polyhydroxybutyrate valerate andblends and copolymers thereof; coatings from polymer dispersions such aspolyurethane dispersions (BAYHDROL®, etc.), fibrin, collagen andderivatives thereof; polysaccharides such as celluloses, starches,dextrans, alginates and derivatives; hyaluronic acid; squaleneemulsions; polyacrylic acid, a copolymer of polylactic acid andpolycaprolactone; medical-grade biodegradable materials such as PGA-TMC,Tyrosine-Derived Polycarbonates and arylates; polycaprolactone co butylacrylate and other co polymers; Poly-L-lactic acid blends with DL-LacticAcid; Poly(lactic acid-co-glycolic acid); polycaprolactone co PLA;polycaprolactone co butyl acrylate and other copolymers;Tyrosine-Derived Polycarbonates and arylate; poly amino acid;polyphosphazenes; polyiminocarbonates; polydimethyltrimethylcarbonates;biodegradable CA/PO₄'s; cyanoacrylate; 50/50 DLPLG; polydioxanone;polypropylene fumarate; polydepsipeptides; macromolecules such aschitosan and Hydroxylpropylmethylcellulose; surface erodible material;maleic anhydride copolymers; zinc-calcium phosphate; amorphouspolyanhydrides; sugar; carbohydrate; gelatin; biodegradable polymers;and polymers dissolvable in bodily fluids; and any combinations thereof.

In some instances a suitable polymer agent or coating comprises blockcopolymers comprising at least one A block and at least one B block. TheA blocks are preferably soft elastomeric blocks, which are based uponone or more polyolefins, or other polymer with a glass transitiontemperature at or below room temperature. For example, the A blocks canbe polyolefinic blocks having alternating quaternary and secondarycarbons of the general formulation: —(CRR′—CF₂)_(n)—, where R and R′are, independently, linear or branched aliphatic groups such as methyl,ethyl, propyl, isopropyl, butyl, isobutyl and so forth, or representcyclic aliphatic groups such as cyclohexane, cyclopentane, and the like,either with or without pendant groups. Preferred polyolefinic blocksinclude polymeric blocks of isobutylene,

(i.e., polymers where R and R′ are methyl groups). Other examples of Ablocks include silicone rubber blocks and acrylate rubber blocks.

The B blocks are preferably hard thermoplastic blocks with glasstransition temperatures significantly higher than the elastomeric Ablocks which, when combined with the soft A blocks, are capable of,inter alfa, altering or adjusting the hardness of the resultingcopolymer to achieve a desired combination of qualities. Examples of Bblocks include polymers of methacrylates or polymers of vinyl aromatics.More specific examples of B blocks include blocks that are (a) formedfrom monomers of styrene

styrene derivatives (e.g., α-methylstyrene, ring-alkylated styrenes orring-halogenated styrenes or other substituted styrenes where one ormore substituents are present on the aromatic ring) or mixtures of thesame, collectively referred to herein as “styrenic blocks” or“polystyrenic blocks” or are (b) formed from monomers ofmethylmethacrylate, ethylmethacrylate, hydroxyethyl methacrylate ormixtures of the same.

The block copolymers are provided in a variety of architectures,including cyclic, linear, and branched architectures. Branchedarchitectures include star-shaped architectures (e.g., architectures inwhich three or more chains emanate from a single region), combarchitectures (e.g., copolymers having a main chain and a plurality ofside chains), and dendritic architectures (including arborescent orhyperbranched copolymers).

Some specific examples of such block copolymers include the following:(a) BA (linear diblock), (b) BAB or ABA (linear triblock), (c) B(AB)_(n)or A(BA)_(n) (linear alternating block), or (d) X-(AB)_(n) or X-(BA)_(n)(includes diblock, triblock and other radial block copolymers), where nis a positive whole number and X is a starting seed, or initiator,molecule. One specific group of polymers have X-(AB)_(n) structures,which are frequently referred to as diblock copolymers and triblockcopolymers where n=1 and n=2, respectively (this terminology disregardsthe presence of the starting seed molecule, for example, treating A-X-Aas a single A block, with the triblock therefore denoted as BAB). Aparticularly beneficial polymer from this group ispolystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS). Wheren=3 or more, these structures are commonly referred to as star-shapedblock copolymers. Other examples of block polymers include branchedblock copolymers such as dendritic block copolymers, wherein at leastone of the A and B blocks is branched, for instance, where the A blocksare branched and are capped by the B blocks.

In the embodiment shown in FIGS. 1-5 the assembly 10 comprises an innershaft 12 and an outer shaft 14 with respective ends of the balloon 16rotatable thereabout. It is noted however, that in some embodiments thecatheter assembly 10 may include a single or inner catheter shaft 12,such as in the embodiment depicted in FIG. 14 for example, wherein bothcollars 30 and 32 are disposed about the same shaft 12. Collars 30 and32 may be rotatable or fixedly engaged to the shaft 12 in the same orsimilar manners as have been previously described. The balloon 16, priorto activation of the EAP material in the collars 30 and 32, is thusrotatable about the single catheter shaft 12. The shaft 12 may be moldedor extruded to include an inflation lumen 42 for inflation of theballoon 16 following electrical activation of the collars 30 and 32.

It may be recognized that in order for the collars 30 and 32 to beelectrically activated to trigger the expansion of the EAP materialtherein, an electric circuit necessarily needs to be formed between theconductive member 50, the current source 60, and each collar 30 and 32.It will be recognized, however, that the presence of saline (e.g. withinbodily fluid such as blood, etc.) within the vessel and/or the ballooninterior 40 during inflation completes the circuit to allow the currentto flow to the collars as desired.

However, in some embodiments the formation of such a circuit may be afunction of the assembly 10 alone. For example in the embodiment shownin FIG. 15, a first conductive wire 50 a is contained within the outershaft 14 or within the inflation lumen 42. Wire 50 a extends from thecurrent source 60 (shown in FIG. 6) to the proximal collar 32 andprovides electrical communication there between. An intermediateconductive member or wire 50 b extends through the wall 45 of theballoon or alternatively through the balloon interior 40 and is incommunication between the collars 32 and 30. A third or interiorconductive member 50 c extends through the inner shaft 12 and is incommunication with the distal collar 30 and extends proximally back tothe current source 60 (shown in FIG. 6) to complete the circuit.

As indicated above, the collars 30 and 32 may be engaged to the balloon16, and more particularly to the respective waists 20 and 22 of theballoon 16 in a variety of manners. Some examples of such engagement areillustrated in FIGS. 16-19.

In the embodiment shown in FIG. 16 the collar 30/32 is integral with theballoon waist 20/22. In this embodiment the collar 30/32 is extruded orco-extruded with the balloon 16. In some embodiments marker 34 maylikewise be co-extruded or may be subsequently secured to the structure.

In some embodiments, such as in the example shown in FIGS. 17 and 19, itmay be desirable to reinforce the waist 20/22 of the balloon 16. In atleast one embodiment the waist 20/22 may be supplemented with one ormore layers 28 of transition material. Where the transition material 28is external to the waist 20/22 as in the embodiment shown in FIG. 19,the layer 28 may reinforce the waist to help insure the fluid tightnessof the balloon seal in the pre-current state and to improve therotational characteristics of the balloon 16. In such an embodiment thelayer 28 may be constructed of one or more strands fibers or layers ofstainless steel or other suitable reinforcing material. In embodimentswhere the waist 20/22 is engaged to the collar 30.32 in the pre-currentstate, such as in FIG. 17,the transition material layer 28 may aid inbonding the material of the waist 20/22 to the material of the collar30/32. Some examples of suitable transition materials for forming thelayer 28 include but are not limited to: Plexar®, Selar®, EMS Hytrel®,etc.

In some embodiments, such as in the example shown in FIG. 18, the use ofa marker such as previously described may be unnecessary. As such acollar 30/32 of EAP may be directly welded or otherwise engaged to thewaist 20/22 or in the alternative to the shaft 12/14.

The above disclosure is intended to be illustrative and not exhaustive.This description will suggest many variations and alternatives to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the claims where the term“comprising” means “including, but not limited to”. Those familiar withthe art may recognize other equivalents to the specific embodimentsdescribed herein which equivalents are also intended to be encompassedby the claims.

Further, the particular features presented in the dependent claims canbe combined with each other in other manners within the scope of theinvention such that the invention should be recognized as alsospecifically directed to other embodiments having any other possiblecombination of the features of the dependent claims. For instance, forpurposes of claim publication, any dependent claim which follows shouldbe taken as alternatively written in a multiple dependent form from allprior claims which possess all antecedents referenced in such dependentclaim if such multiple dependent format is an accepted format within thejurisdiction (e.g. each claim depending directly from claim 1 should bealternatively taken as depending from all previous claims). Injurisdictions where multiple dependent claim formats are restricted, thefollowing dependent claims should each be also taken as alternativelywritten in each singly dependent claim format which creates a dependencyfrom a prior antecedent-possessing claim other than the specific claimlisted in such dependent claim below.

With this description, those skilled in the art may recognize otherequivalents to the specific embodiment described herein. Suchequivalents are intended to be encompassed by the claims attachedhereto.

1. A medical device, comprising: an elongate shaft including a proximalregion, a distal region, and a lumen extending at least partiallytherebetween; a balloon disposed about the distal region of the elongateshaft, the balloon comprising an electroactive polymer, wherein theelectroactive polymer is configured to be electrically actuated betweena non-activated configuration and an activated configuration, whereinthe activated configuration is different than the non-activatedconfiguration; a current source configured to provide an electricalcurrent for selectively electrically actuating the electroactivepolymer; and a conductive member in electrical communication with thecurrent source and the electroactive polymer, wherein the conductivemember is configured to transmit the electrical current from the currentsource to the electroactive polymer, wherein the conductive memberextends along at least a portion of the distal region of the elongateshaft.
 2. The medical device of claim 1, wherein the electroactivepolymer is in the activated configuration when exposed to the electricalcurrent, and wherein the electroactive polymer is in the non-activatedstate when not exposed to the electrical current.
 3. The medical deviceof claim 1, wherein the activated configuration of the electroactivepolymer is an expanded configuration relative to the non-expandedconfiguration.
 4. The medical device of claim 1, wherein the conductivemember is at least partially enclosed by the elongate shaft.
 5. Themedical device of claim 1, wherein the conductive member is co-extrudedwith the elongate shaft.
 6. The medical device of claim 1, wherein theelectroactive polymer includes a material selected from at least onemember of the group consisting of Poly-pyrrole (PPY), Poly-Aniline(PAni), Poly-Thiofene (PTH), Poly-Paraphenylene Vinylene (PPV), Nafion®,Bucky paper, and any combination thereof.
 7. The medical device of claim1, further comprising one or more therapeutic agents, wherein themedical device is configured to deliver the one or more therapeuticagents to a delivery site within a vessel.
 8. The medical device ofclaim 7, wherein the one or more therapeutic agents is at least onenon-genetic therapeutic agent selected from at least one member of thegroup consisting of: anti-thrombogenic agents including heparin, heparinderivatives, urokinase, and PPack (dextrophenylalanine proline argininechloromethylketone); anti-proliferative agents including enoxaprin,angiopeptin, monoclonal antibodies capable of blocking smooth musclecell proliferation, hirudin, and acetylsalicylic acid; anti-inflammatoryagents including dexamethasone, prednisolone, corticosterone,budesonide, estrogen, sulfasatazine, and mesalamine;antineoplastic/antiproliferative/anti-miotic agents includingpaclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine,epothilones, endostatin, angiostatin and thymidine kinase inhibitors;anesthetic agents including lidocaine, bupivacaine and ropivacaine;anti-coagulants including D-Phe-Pro-Arg chloromethyl keton, an RGDpeptide-containing compound, heparin, antithrombin compounds, plateletreceptor antagonists, anti-thrombin antibodies, anti-platelet receptorantibodies, aspirin, prostaglandin inhibitors, platelet inhibitors andtick antiplatelet peptides; vascular cell growth promoters includinggrowth factor inhibitors, growth factor receptor antagonists,transcriptional activators, and translational promoters, vascular cellgrowth inhibitors including growth factor inhibitors, growth factorreceptor antagonists, transcriptional repressors, translationalrepressors, replication inhibitors, inhibitory antibodies, antibodiesdirected against growth factors, bifunctional molecules consisting of agrowth factor and a cytotoxin; bifunctional molecules consisting of anantibody and a cytotoxin; cholesterol-lowering agents; vasodilatingagents; agents which interfere with endogenous vascoactive mechanisms,and any combinations thereof.
 9. The medical device of claim 7, whereinthe one or more therapeutic agents includes paclitaxel.
 10. The medicaldevice of claim 7, wherein the one or more therapeutic agents is atleast one non-genetic therapeutic agent selected from at least onemember of the group consisting of: anti-thrombogenic agents; anti-proliferative agents; anti-inflammatory agents;antineoplastic/antiproliferative/anti-miotic agents; anesthetic agentsincluding lidocaine, bupivacaine and ropivacaine; anti-coagulants;vascular cell growth promoters; vascular cell growth inhibitors;bifunctional molecules consisting of an antibody and a cytotoxin;cholesterol-lowering agents; vasodilating agents; and agents whichinterfere with endogenous vascoactive mechanisms, and any combinationsthereof.
 11. The medical device of claim 1, wherein the balloon includesone or more collars comprising the electroactive polymer.
 12. A medicaldevice, comprising: an elongate shaft including a proximal region, adistal region, and a lumen extending at least partially therebetween; aballoon disposed about the distal region of the elongate shaft, theballoon comprising an electroactive polymer, wherein the electro activepolymer is configured to be electrically actuated between anon-activated configuration and an activated configuration, wherein theactivated configuration is an expanded configuration relative to thenon-activated configuration; a current source configured to provide anelectrical current for selectively electrically actuating theelectroactive polymer; a conductive member in electrical communicationwith the current source and the electroactive polymer, wherein theconductive member is configured to transmit the electrical current fromthe current source to the electroactive polymer, wherein the conductivemember extends along at least a portion of the distal region of theelongate shaft; and one or more therapeutic agents for treating a vessel13. The medical device of claim 12, wherein the electroactive polymer isin the activated configuration when exposed to the electrical current,and wherein the electroactive polymer is in the non-activated state whennot exposed to the electrical current.
 14. The medical device of claim12, wherein the conductive member is at least partially enclosed by theelongate shaft.
 15. The medical device of claim 12, wherein theconductive member is co-extruded with the elongate shaft.
 16. Themedical device of claim 12, wherein the therapeutic agent includes atleast one polymer agent or coating.
 17. The medical device of claim 12,wherein the one or more therapeutic agents include paclitaxel.
 18. Amethod of treating a vessel, the method comprising: providing a catheterassembly, the catheter assembly including: an elongate shaft including aproximal region, a distal region, and a lumen extending at leastpartially therebetween a balloon disposed about the distal region of theelongate shaft, the balloon comprising an electroactive polymer, whereinthe electroactive polymer is configured to be electrically actuatedbetween a non-activated configuration and an activated configuration,wherein the activated configuration is an expanded configurationrelative to the non-activated configuration; a current source configuredto provide an electrical current for selectively electrically actuatingthe electroactive polymer; and a conductive member in electricalcommunication with the current source and the electroactive polymer,wherein the conductive member is configured to transmit the electricalcurrent from the current source to the electroactive polymer, whereinthe conductive member extends along at least a portion of the distalregion of the elongate shaft; advancing the catheter assembly throughthe vessel to a target location of the vessel; after the catheterassembly has been advanced to the target location of the vessel,electrically activating the electroactive polymer; and delivering one ormore therapeutic agents to the target location of the vessel.
 19. Themethod of claim 18, wherein the electroactive polymer includes amaterial selected from at least one member of the group consisting of:Poly-pyrrole (PPY), Poly-Aniline (PAni), Poly-Thiofene (PTH),Poly-Paraphenylene Vinylene (PPV), Nafion®, Bucky paper, and anycombination thereof.
 20. The method of claim 18, wherein the one or moretherapeutic agents include paclitaxel.
 21. A balloon catheter,comprising: an inner tubular member including a proximal end and adistal end; an outer tubular member including a proximal end and adistal end, the outer tubular member disposed about the inner tubularmember such that a distance between an outer surface of the innertubular member and an inner surface of the outer tubuler member definesan inflation lumen, wherein the distal end of the inner tubular memberextends distally of the distal end of the outer tubular member; aballoon including a proximal waist and a distal waist, the proximalwaist disposed about the outer tubular member and the distal waistdisposed about the inner tubular member, wherein the balloon is in fluidcommunication with the inflation lumen, the balloon including anelectroactive polymer that is configured to be electrically actuatedbetween a non-activated configuration and an activated configuration,wherein the activated configuration is different than the non-activatedconfiguration; a current source configured to provide an electricalcurrent for selectively electrically actuating the electroactivepolymer; and a conductive member in electrical communication with thecurrent source and the electroactive polymer, wherein the conductivemember is configured to transmit the electrical current from the currentsource to the electroactive polymer, wherein the conductive memberextends along at least a portion of the inner tubular member or theouter tubular member.
 22. The balloon catheter of claim 21 furthercomprising one or more therapeutic agents for treating a vessel.